Insole and method of making same



H. WARREN INSOLE AND METHOD 0F MAKING SAME March 23, y193 7.

Filed May 2o, 1955 www" Patented Mar. 23, 1937 UNITED .sT/criss PATENT OFFICE INSOLE AND METHOD OF MAKING SAME Application May 20,

8 Claims.

N This invention relates to insoles and to methods of making insoles and is illustrated herein with particular reference to insoles adapted for use in welt shoes.

In the manufacture of Welt shoes a leather insole of substantial thickness is usually channeled to form inner and outer lips and a shoe upper and welt' are then secured in overlasted relation to the insole by inseam stitches which pass 10 through the between substance separatingl the two channels. The inner loops of these stiches are concealed in the inside channel and are lovcated below the exposed surface of the insole so that the outside lip andthe excess upper materials can be trimmed without danger of severing the inseam stitches. Various attempts have been made to utilize insoles of thinner leather in such shoes and also to substitute light weight insoles of artificial leather inorder to increase the ilexibility of the shoes and to reduce expense in their manufacture. VHowever, because of the channels necessary to provide the lasting ribs and stitchreceiving grooves, light weight insoles of the types referred to have proved unsatisfactory, the leather insoles being too thin to permit the channels to be formed properly, and the artificial i leather insoles having a tendency tov peel or tear away when stresses or strains areput on the lips. Objects of the present invention are to provide an improved light weight insole for use in shoes in which the upper is secured in lasted position by attachment to a rib or lip, and to provide an improved method of making such insoles.

In accordancewith the foregoing a feature of the invention resides in the provision of a thin insole of articial leather material having a -lasting lip or rib to which a shoe upper may be secured and having a groove adapted to receive f the stitches which formthe inseam of a Welt shoe. As illustrated herein, the insole is made up of a plurality of layers of cellulosic or fibrous material such, for example, as wood fiber plus a binding agent, said layers being reinforced at least at their marginal portions with fabric material located between the layers and secured thereto by an adhesive compatible with the binding agent so that the adhesive unites readily therewith. The fabric material as herein illustrated may be a continuous layer or, if desired, may be astrip coextensive with only the marginal portions of the fibrous layers. The binding agent may be an aqueous rubber dispersion preferably in the form of natural rubber latex or lit maybe latex prepared from crude or reclaimed rubber. 'I'he adhesive which unites with the binding agent is 1935, Serial No. 22,368

latex cement or a derivative thereof. The combining of these materials results in a bond between the several layers of the insole which is strong enough to resist any tendency toward separation or peeling of the layers during the construction of the shoe or during its Wear.

In accordance with another feature of the invention,`the lasting rib or lip is formed, as herein illustrated, by the upturned margins of the outer brous layer of the insole and the fabric material which is secured thereto, the fabric being separated from the inner brous layer, for example, by channeling o r, if desired, by omitting cement between the fabric material and the margin of the lower layer when the members are initially secured together. A lasting rib is thus provided on the outer face of the insole and a reduced feather portion over which the upper may be lasted without any danger of the layers tearing or peeling inwardly of the-lip, since the inner material is not merely artificial leather in its normal condition but comprises separate layers reinforced by fabric and securely bonded together by cement which unites readily with the fibrous material and thus resists any tendency to separate through strain or pressure on the lip.

The insole is also provided, in accordance with still another feature of the invention, with a stitch-receiving recess or groove in which the inseam stitches that secure the shoe upper andwelt to the insole may be located. This groove, as illustrated herein, is located at the inner side of the base of the lasting rib and is formed by compression of the brous material of the outer layer of the insole. The bottom of the groove inclines upwardly from, the rib toward the central portion of the insole and thereby facilitates the action of the curved needle of the sewing machine which inserts the inseam stitches. Since the material through which the stitches pass is compacted or compressed in forming the groove it will assistln producing a tighter inseam than could otherwise be obtained.

In its method aspects the invention provides an improved process for producing light Weight insoles for welt shoes which consists in forming the body portion of an insole of layers of cellulosic or fibrous material such as Wood pulp loosely compacted and held together by a latex binding agent. The brous layers are reinforced with a marginal strip or a continuous layer of fabric material interposed between the two layers and secured to each by latex cement so that the uniting of the latex binder with the cement produces a strong permanent bond. The margins of the CAS fabric material and the inner brous layer may be separated either by omitting cement therebetween or-by splitting after the members have.I been secure-d together. The margins of the outer 5 fibrous layer and the fabric material are then turned up to form a lasting .rib on the insole, this being preferably done after the layers have been cemented together although, if desired, the rib may be formed by cementing the fabric material l0 to the outer layer and turning up the lip before these layers are cemented to the inner layer of the insole.

The stitch-recelving groove is formed, as herein illustrated, by applying localized pressure progressively to the outer layer at the inner side of,

the base of the lasting rib and the pressure is so applied that the bottom of the groove inclines upwardly from the rib toward the surface of the insole thereby producing a relatively wide groove which facilitates the inserting of the inseam stitches in the shoe while permitting these stitches to be located below the outer or exposed face of the insole where they might be severed during the subsequent trimming operation. With the above and other objects and features inv view the invention will now be described in connection with the accompanying drawing and thereafter pointed out in the claims.

In the drawing, Fig. 1 is a perspective view of the members which form the insole of the present invention; Fig. 2 is a transverse sectional View on an en larged scale showing the members of Fig. l secured together;

Fig. 3 is a transverse sectional View showing4 the margins of the outer and intermediate layers of the insole turned up to form a lasting rib and illustrating the method of forming a stitch-receiving groove in the outer layer; Fig. 4 is a perspective view of the parts of an insole forming a modification of the invention;

Fig. 5 is a transverse sectional view of the insole parts shown in Fig. 4 secured together and provided with a lasting rib and stitch-receiving groove; and

Fig. 6 is a fragmentary sectional view of a portion of a welt shoe having one of the insoles o f the present invention embodied therein.

In practising the method of the present inven- .'50` tion a plurality of insole blanks of the proper size and shape is died out of -a large sheet of artificial leather material from which the insoles are to be. made, this material comprising cellulose or wood fiber impregnated with an aqueous rubber dispersion such as natural rubber latex or an artificial dispersion thereof, as disclosed in Letters Patent of' the UnitedStates No. 1,891,027, granted Dec. 13, 1932, on an application filed in the name of George H. Richter. As described in 6o the patent referred to, this artificial leather material is made by forming a web of unbeaten or very lightly beaten wood pulp or fiber which iS thereafter partially dewatered by passing it over rolls maintained under light suction but which c5is not subjected to any mechanical pressure devices 'so that the bers of the resulting web are not compacted and are therefore highly bibulous and absorptive. The web is then impregnated with a binding agent comprising an aqueous rubber dispersion of latex after which it is passed through rolls which serve to remove only the excess dispersion from the web without effecting any appreciable compacting of its fibers, the water of the dispersion being thereafter removed by evaporation rather than compression. `This material may be produced in single layers or it may be made as a multi-ply product in which case a plurality of webs are simultaneously lmpregnated with a rubber latex dispersion and then superposed and united by pressurevrolls prior to drying. By passing the multi-ply web through a coagulating medium a flrm bonding together of the contacting faces of the webs by the coagulated rubber is effected.

The insole blanks indicated in Fig. 1 by the numerals IIJ and I2 form, respectively, the outer and inner fibrous layers of the insole. A sheet of fabric material I4, conforming in outline to the insole blanks I0 and I2 and extending rearwardly substantially to the heel breast line, ls interposed between the blanks and is secured thereto by an adhesive such as latex cement which contains rubber as a binding agent and which consequently unites readily with the latex dispersion which forms the binding agent of the artificial leather comprising the inner and outer layers'. In cementing the parts together latex is preferably applied to the adjacent sides of the inner and outer fibrous layers and the fabric material I4 is then positioned on one of the layers' after which the three layers are subjected to pressure sufficient to cause them to become firmly attached together without any appreciable compression of the inner and outer layers. 'I'he latex cement on each side of the fabric material will have a tendency to penetrate through the fabric material and unite with the latex binder in both the inner and outer layers, thereby producing a multi-ply insole which,'because of the materials incorporated therein, will have practically no tendency to split or peel through separation of the various layers even under substantial strain.

'I'he insole is next provided with a lasting rib I6 composed of the. outer layer I0 and the intermediate or reinforcing layer I4 of -fabric material, the marginal portions of the fabric layer and the inner fibrous layer I2 being separated in any well-known or usual manner, such as by channeling, and the outer and intermediate layers being then turned up substantially at right angles to the plane of the opposite surfaces of the insole, as shown in Fig. 3. If more convenient the marginal portion of the inner layer I2 may be left free of cement when the layers are initially secured together so that the margin of l,

the fabric material will adhere only to the outer layer I0. The rib or lip may be formed by hand or with the aid of any well-known lip turning machine and it is within the scope of the invention to cement the fabric material I4 to the outer layer I0 and then to turn up the marginal materials to form the lip I6 before these two layers are secured to the lower layer I2, should this method be found more convenient or desirable. The lip I6 should be spaced inwardly from the edge of the insole a distance suiiicient to form a feather portion over which the shoe upper may be lasted and the lip should extend around the insole rearwardly to the heel breast line.

Since the insole is adapted particularly for welt work it is provided with a recess or groove adjacent to the inner side of the base of the rib I6 for receiving the inseam stitches which secure the upper and welt to the insole in the construction of a welt shoe, this groove being indicated in Fig. 3 by the numeral I8. In accordance with the present method the groove I8 is formed by compressing the material of the outer layer Ill with the aid of .a rotary tool or roll 20 while the insole is supported on a base plate 22. In this III) Way localized pressure is applied progressively around the insole adjacent to the rib I6 so that only the material at the base of the rib and a short distance inwardly thereof is compressed. As shown in Fig. 3, the roll 20 is preferably of a frusto-conical shape with the smaller diameter nearer the central portion of the insole so that it forms a groove the bottom surface of which inclines upwardly from the base of the rib to the 19 outer surface of the insole. The groove I8 thus produced not only permits the stitches which form the inseam in the finished shoe to be located below the outer surface of the central portion of the insole but also facilitates the inserting of such stitches in a plane below said surface by compressing the material inwardly of the rib which the curved needle of the welt sewing machine might otherwise engage. In other words, the angle of the surface of the groove I8 approxi- 20 mates the angle of the inner channel in a usual welt insole which is positioned at an angle that permits the needle of the sewing machine to pass through the between substance of the insole Without engaging a shoulder or ridge inwardly of the lasting rib,

As shown in Figi. 3, the material of the outer layer ID of the insole `is compressed by the roll 20 without any substantialcompression of the inner layer l2 since the pressure of the roll is localized and passes progressively around the insole without any considerable dwell at any one point. The'compression of the material through which the inseam stitches pass also results in a tight inseam which holds the upper firmly in lasted position. Fig. 6 shows the insole of Fig. 3 embodied in a welt shoe the upper 24 of which has been secured to the rib I6 by inseam stitches 26 and an outsole 28 thereaftersecured to the welt 30 by stitches 32.

A modification of the invention, which is illustrated in Figs. 4 and 5, consi'sts in securing between the margins of outer and inner layers 34, 36 of artificial leather material of the character referred to above, a marginal strip 38 of fabric material which is cemented between the two layers by latex cement in the manner already described.V The layers 34 and 36 are then cemented together by latex and the marginal portions of the outer layer 34 and of the fabric 38 are turned up as shown in Fig. 5 to form the lastingrib 40, the marginal portions of the inner layer 36 forming the reduced feather portion of the insole over which a shoe upper may be lasted. The outer layer 34 is then compressed along the inner side of the base of the rib 40 to form an inclined groove 42 for receiving the inseam stitches of a welt shoe. The-insole of Figs. 4 and 5 is well adapted for embodiment in a welt shoe vsuch as that illustrated in Fig. 6, and, where economy in materials is a factor, may be preferable to the insole illustrated in Figs, 1 to 3, inclusive. Since the strip of fabric material 38 does not cover the central or intramarginal portion of the insole, a

little more filler material may be needed in the shoe bottom after the trimming operation in order to make up the difference between the thickness of the insole at the marginal portions and at its central portion. The amount of extra filler material necessary to offset this difference in thickness, however, will be so small that'it will have no detrimental effect upon the finished shoe either with respect to its Weight, flexibility or appearance.

While the insoles disclosed herein are particu- 75 larly adapted for use in the construction of welt shoes, it is to be understood that merely by eliminating the stitch-receiving grooves I8 and 42 the insoles are equally Well adapted for use in the manufacture of other types of shoes, for example, shoes having uppers secured in overlasted position by cement and in which the upper is secured to upstanding ribs by staples or other fastenings while the cement is setting. Moreover, byv forming the stitch-receiving grooves in the insoles it is possible in such shoes to locate the staples which hold the upper temporarily in lasted position closer tothe body portion of the insole and thus permit a closer trimming operation to be performed in cases where it may be desirable to have some of the staples remain permanently in certain portions of the shoe bottom to provide a firmer attachment of the upper to the insole.

Having described my invention, what I claim'as new and desire to secure by Letters Patent of the s United States isz.

1. A built-up insole for shoes comprising inner and outer layers of wood fiber plus a latex binding agent, an intermediate layer of fabric material secured to said layers by latex cement, a lasting rib adjacent to the margin of said insole formed by the margins of said outer layer and said intermediate layer, and a stitch-receiving groove at -the inner side of the base of said rib formed by compression of the material of said outer layer.

2. An insole for welt shoes comprising inner and outer layers of fibrous material plus a latex binding agent, an intermediate reinforcing layor of fabric material, said layers being secured together with latex cement, and a lasting rib formed by the upturned margins of the outer fibrous layer and the intermediate fabric layer.

3. An insole for welt shoes comprising inner and outer layers of compressible fibrous material plus a latex binding agent, an'intermediate layer of fabric secured to said inner and outer lay.- ers by latex cement, a lasting rib adjacent to )the margin of said insole formed by the upturned margins of said outer layer and said fabric lay'- er, and a stitch-receiving groove in said outer layer at the inner side of the base of said rib, the material of. said outer layer adjacent to the groove being compressed, said material being compressed more adjacent to the rib than farther inwardly from the rib so that the bottom of the groove inclines upwardly toward the central portion of the insole, thereby facilitating the inserting of the inseam stitches during the construction of a shoe.

4. An insole for welt shoes comprising inner and outer layers of wood fiber plus a latex binding agent, a reinforcing strip of fabric material coextensive with the margins of said layers and secured thereto by latex cement, a rib formed by the upturned marginal 'portions of said reinforcing strip and the outer fibrous layer. and a stitch-receiving groove in said outerlayer at the inner side 'of the base of said rib, the material adjacent to said groove being compressed and said groove having its bottom surface inclined upwardly toward the central portion cf-the insole to facilitate the inserting of the inseam stitches during the construction of.

a shoe.

5. Ihat improvement in methods of making insoles for shoes which consists in forming the body portion of an insole of inner and outer layers of fibrous material plus a latex binding agent, reinforcing said layers lwith a layer of fabric material located between them, securing said fibrous and fabric layers together with latex cement, turning up the marginal portions of said outer layer and the fabric layer to form a lasting rib, and compressing the material of said outer layer by localized pressure applied progressively along the base of the rib to form a groove for receiving the stitches which are to form the inseam in the finished shoe.

6. That improvement in methods of making insoles for welt shoes which consists in forming the body portion of an insole of inner and outer layers of Wood fiber plus a latex binding agent. reinforcing said layers with an intermediate layer of fabric material, securing said intermediate layer to the ber layers with latex cement, turning up the margins of the outer layer and the intermediate layer to form a lasting rib and a reduced feather portion on the insole, and compressing the material of the outer layer at the inner side of the base of the rib by pressure applied progressively both longitudinally and transversely of said layer to form a stitchreceiving groove the bottom surface of which in- 25 clines upwardly from the rib toward the central portion of the insole to facilitate the inserting of the 'inseam stitches in the construction of a shoe.

7. That improvement in methods of making insoles for shoes which consists in forming the body portion of an insole of layers of fibrous material plus a latex binding agent, reinforcing the `layer of fabric material, said layers being secured together with cement containing rubber as a b inding agent, and a lasting rib formed by the upturned margins of the outer fibrous layer and the intermediate fabric layer.

HAROLD WARREN. 

